JP3851400B2 - Driving device for casing drilling type earth drill - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a casing excavation type earth drill driving device that rotationally drives a kelly bar and a casing tube by a kelly bar driving shaft.
[0002]
[Prior art]
The casing excavation type earth drill performs the pushing operation of the casing tube and the excavation work in the casing tube by the kelly bar by one machine. Conventionally, the driving device for the casing tube and the kelly bar is as shown in FIG. Further, the casing tube rotating cylinder 2 is formed integrally with the kelly bar drive shaft 1, and the gear 6 fixed to the kelly bar drive shaft 1 is meshed with the gear 5 fixed to the output shaft 4 of the hydraulic motor 3. The kelly bar 7 inserted through the casing 1 and the casing tube 8 attached to the casing tube rotating cylinder 2 are rotationally driven.
[0003]
[Problems to be solved by the invention]
However, in the above-described configuration, the rotational speed of the kelly bar and the rotational speed of the casing tube are the same, so the rotational torques of both are the same, but the torque that rotationally drives the casing tube is 2 to 2 of the torque that rotationally drives the kellyba. Since it is required more than 3 times, when pushing the casing tube, the hydraulic motor is rotated at a low speed to generate high torque, and when excavating by the kelly bar, the hydraulic motor is rotated at a high speed to reduce the torque. Required.
[0004]
In some cases, the excavation work by the kelly bar and the push-in operation of the casing tube are simultaneously performed. In this case, a torque exceeding the permissible value is applied to the kelly bar, which may lead to a breakage accident of the kelly bar. Furthermore, a kelly bar that can withstand the torque required for the pushing operation of the casing tube is not practical in terms of weight and cost.
[0005]
Accordingly, the present invention provides a casing excavation type earthing that can generate the rotational torque of the kelly bar and the rotational torque of the casing tube as appropriate amounts, respectively, even with a small hydraulic motor without performing an operation for switching the rotational speed of the hydraulic motor. It aims at providing the drive device of a drill.
[0006]
[Means for Solving the Problems]
In order to achieve the above-described object, the present invention provides a casing excavation type earth drill driving device in which a kelly bar and a casing tube are rotationally driven by a kelly bar driving shaft, and the kelly bar driving shaft is rotatably arranged in a vertical direction on a case. And the kelly bar is inserted in a kelly bar insertion hole formed in the kelly bar drive shaft in a vertically slidable and rotationally restrained relationship, and the gear fixed to the upper portion of the kelly bar drive shaft is inserted into the gear. A gear fixed to an output shaft of a hydraulic motor disposed above the case is meshed, and a casing tube rotating gear is fixed to a lower portion of the Kelly bar drive shaft protruding from the lower portion of the case, and the casing tube rotating gear is fixed. Is engaged with a planetary gear rotatably provided on a shaft protruding from the lower part of the case, and a casing tube Provided cylinder rotatably, and characterized in that meshes with the planetary gears in an internal gear formed in the upper inner circumference of the casing tube rotating cylinder.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on the embodiments shown in FIGS. The earth drill 10 supports a leader 12 erected on the front part of a main body 11 with a pair of backstays 13 so as to be able to be raised and lowered, and a kelly bar 14 and a drive device 16 for a casing tube 15 are arranged on the leader 12 so as to be movable up and down. Has been established.
[0008]
The kelly bar 14 is formed in a shape in which a plurality of protruding keys are provided on a square cross section or a round peripheral surface, and is suspended by a wire rope 18 suspended from the top sheave 17 of the reader 12 so as to be lifted and lowered. The kelly bar insertion shaft 20 formed in the kelly bar drive shaft 19 is slidable in the vertical direction, and is inserted in a rotational relationship with a restriction, and a cylindrical excavating bucket 21 is attached to the lower end.
[0009]
The driving device 16 has the kelly bar driving shaft 19 rotatably disposed in the vertical direction at the substantially central portion of the case 22, and is disposed above the case 22 on a gear 23 fixed to the upper portion of the kelly bar driving shaft 19. A gear 26 fixed to the output shaft 25 of the hydraulic motor 24 is engaged.
[0010]
Further, a casing tube rotating gear 27 is fixed to the lower portion of the kelly bar drive shaft 19 protruding from the lower portion of the case 22, and the casing tube rotating gear 27 is rotatable on a shaft 28 protruding from the lower portion of the case 22. The planetary gear 29 provided is meshed.
[0011]
A casing tube rotating cylinder 30 is rotatably provided at the lower portion of the case 22, and an internal gear 31 is formed on the inner periphery of the upper portion of the casing tube rotating cylinder 30. The toothed gear 31 is engaged. The casing tube 15 is attached to the lower part of the casing tube rotating cylinder 30 so as to be integrally rotatable.
[0012]
With this configuration, when the kelly bar drive shaft 19 is rotationally driven by the hydraulic motor 24, the rotating torque of the casing tube 15 becomes several times higher than the rotating torque of the kelly bar 14. The rotational torque of 14 and the rotational torque of the casing tube 15 can be generated as appropriate amounts.
[0013]
Therefore, it is not necessary to switch the rotation speed of the hydraulic motor 24 during excavation work by the kelly bar 14 and when the casing tube 15 is pushed in, so that the operation is facilitated. Further, when the excavation work by the kelly bar 14 and the pushing operation of the casing tube 15 are performed at the same time, the breakage accident of the kelly bar 14 can be prevented, so that the work efficiency and the total performance can be improved. If the shaft 28 has a structure that can be fixed to and released from the case 22, only the excavation work by the kelly bar 14 can be performed without rotating the casing tube 15.
[0014]
【The invention's effect】
As described above, the casing excavation type earth drill driving device of the present invention has a planetary gear that is fixed to a casing tube rotating gear on a kelly bar drive shaft that rotates the kelly bar and meshes with the casing tube rotating gear; Since the casing tube rotating cylinder having the internal gear that meshes with the planetary gear is provided, the rotating torque of the casing tube can be several times higher than the rotating torque of the Keriba. The rotational torque of the tube can be generated as an appropriate amount for each.
[0015]
Accordingly, it is not necessary to switch the rotation speed of the hydraulic motor during excavation work by the kelly bar and during the push-in operation of the casing tube. In addition, when performing excavation work by the Keriba and the pushing operation of the casing tube at the same time, it is possible to prevent a Keriba breakage accident, so that work efficiency and total performance can be improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a driving apparatus showing an embodiment of the present invention.
FIG. 2 is a front view of the ground drill.
FIG. 3 is a cross-sectional view of a conventional drive device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Earth drill, 14 ... Keriba, 15 ... Casing tube, 16 ... Drive apparatus, 19 ... Kelly bar drive shaft, 24 ... Hydraulic motor, 27 ... Gear for rotating casing tube, 29 ... Planetary gear, 30 ... Casing tube rotary cylinder, 31 ... Internal gear

Claims (1)

In a casing excavation type earth drill driving device that rotationally drives a kelly bar and a casing tube by a kelly bar driving shaft , the kelly bar driving shaft is rotatably arranged in a vertical direction in a case, and the kelly bar is used as the kelly bar driving shaft. Inserted into the formed kelly bar insertion hole in a vertically slidable and constrained rotation relationship, inserted into a gear fixed to the upper part of the kelly bar drive shaft, to the output shaft of the hydraulic motor disposed above the case The fixed gear is meshed, and the casing tube rotating gear is fixed to the lower part of the kelly bar drive shaft protruding from the lower part of the case, and the casing tube rotating gear is rotated to the shaft protruding from the lower part of the case. A planetary gear provided freely is meshed, and a casing tube rotating cylinder is rotatably provided at the lower part of the case. Casing drilling type earth drilling apparatus for driving, characterized in that the upper inner internal gear formed on the circumference of the blanking rotary cylinder in mesh with said planetary gear.

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